Resolution of Tocainide and Its Analogues on Liquid Chromatographic Chiral Stationary Phases Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid

Two liquid chromatographic chiral stationary phases (CSPs) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid were successfully applied in the resolution of racemic tocainide and its analogues. In the resolution of tocainide, especially, the CSP containing N-CH₃ amide tethering groups was quite effective, showing clear baseline resolution (RS: 2.66) with reasonable enantioselectivity ( a: 1.25). Consequently, the CSP containing N-CH₃ amide tethering groups is expected to be useful to monitor the enantiomeric composition of tocainide in clinical samples. In addition, the chromatographic behaviors for the resolution of tocainide and its analogues on the two CSPs were found controllable by varying the content and the type of organic and acidic modifiers in aqueous mobile phase.